MORE RECENT EDIT: After the initial failure, I decided to do the next best
thing, and write a short program for the ESP8266 that will generate a random
seed every time it boots up and print it to a screen. That should be a good
compromise, and it works well, scroll down to see it.

OLDER EDIT: I have been informed that BIP39 derives the last word from SHA
hash of all the others, and thus needs a computer to generate the seeds. Thus,
this post is moot and useless. I will leave the post here as a mahnmal, in the
hope that someone will find something in it useful.

Being the geek that I am, I find Bitcoin fascinating (if only everybody focused
on something other than the price!), and hardware
wallets doubly so. If you haven’t heard of
them, hardware wallets are small, flash-drive-sized devices that usually connect
to a computer’s USB port and hold your wallet keys. That way, even if the
computer you’re trying to send bitcoins from is riddled with viruses, you remain
very secure and nobody but you can pay on your behalf. Unsurprisingly,
I bought one! I was between the Trezor and the Ledger
Nano S, but I decided on
the Nano S in the end, as their platform looks more exciting, more secure and
I was quite satisfied from the two
HW1s I had bought for cheap
at a sale.

However, since I’m in it for the technology and cryptoparanoia, rather than for
any practical purpose, I find that hardware wallets have a few issues. For
a short primer, a hardware wallet’s main advantage is that the keys are
generated on the device and never, ever leave it, as whoever has the keys can
spend your money. Since the keys never leave the device, though, you’re
screwed if you ever lose it. To avoid that, wallet designers usually allow you
to do a one-time export of the keys (many devices have a screen they show you
the keys on), right after creating them. The export is usually a Bitcoin
standard
called BIP39,
and is usually in the form of 12 or 24 everyday words, which you write down on
a piece of paper, store it in your safe, and that’s all that’s needed to
retrieve your keys if you lose the hardware wallet. No computer ever touches the
keys, and you can sleep peacefully.